In general, crops have usually been cultivated on land whatever the type may be. However, such cultivation is dependent upon the configuration of the ground, size of the cultivation areas, cultivation condition, cultivation circumstances etc. Furthermore, cultivation of crops on land is sometimes subject to air pollution noxious insects or plant diseases and considerable damage often results. The present invention resolves the above mentioned difficultes by providing an installation for crop cultivation on a body of water and by utilizing solar energy. The technique can widely be developed and utilized to provide a remaining huge cultivation area on bodies of water for future use. Such cultivation areas are free from the restrictions inherent in crop cultivation on land.